Taking out a Mortgage on a house I already fully own

Hi All!

I want to buy a house (all cash) then rent the house out. While the house is being rented I would like to take out a mortgage to then buy another house and rent that one out.

I wanted to know what people experience has been so far? In general, how would the process work? what do I need to look out for?

TIA

It is better to buy first home with loan and then 2nd home with another loan.

How the calculations, look out this thread